There’s a certain manufacturer that makes carbon-based friction material in the form of a disk. A press and die are used in the final manufacturing operation to cure the carbon material into a functioning friction pad. Peak temperature uniformity is a critical characteristic during the cure cycle. Eight thermocouples are placed in the die to capture the temperatures during the cure cycle. Each cycle’s peak temperature at each thermocouple is recorded for SPC purposes.

As the company’s statistical process control expert, what’s the most appropriate and efficient charting method to determines patterns of uniformity of the peak temperatures among the eight thermocouple locations?

A) An x-bar and range chart with a sample size of eight.
B) A group individuals and moving-range chart with eight process streams.
C) An x-bar and sigma chart with a sample size of eight.
D) Eight individuals and moving-range charts—one for each thermocouple location.
E) A Target 3D x-bar and sigma chart with a sample size of eight.

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